This invention relates to inspection of edges.
The sharpened edges of razor blades, for example, are typically inspected after the blades have been cut from a strip of steel that has been passed through a sharpening machine. An operator transfers the razor blades to spindles to form a block of blades with the sharpened edges of the blades all facing in the same direction. Defects are detected by holding the block of blades with the sharpened edges at different angles with respect to a light source and looking for stray reflections of light that indicate damaged blades.
To remove a defective blade from the block of blades the operator transfers a section of good blades from the block onto another set of spindles and removes and discards several blades from the block in the vicinity of the reflection. The operator then transfers the good blades back onto the original spindles and again checks for defects.